Processing Type 1: All images were flattened with a corresponding image of white surface. The flats were smoothed by blurring with a gaussian-like filter, normalized to have a maximum value of unity and divided into the corresponding spectral image.

Processing Type 2: A pseudocolor image created from an image with ultraviolet illumination, either straight (365) or through a blue (CFUB) or a green (CFUG) color filter, and a long-wave image (630, 735, or 780). The two images are locally stretched over a sliding window to normalize values within 3 standard deviations around the mean value. The adjusted ultraviolet image is put into the green and blue separations of the pseudocolor image and the adjusted long-wave image is recorded in the red separation.

Processing Type 1: No

Processing Type 2: Yes

Processing Type 1: globally adjusted

Processing Type 2: Locally adjustable over a sliding window

Processing Type 1: linear stretch

Processing Type 2: Color and image enhancement

Processing Type 1: 1.2

Processing Type 2: 1.2

Processing Type 1: Archie 1.2, rect, div

Processing Type 2: Archie 1.2, pseudomask, pseudoratio and otsumask

Processing Type 2: Local contrast adjustment computed on image after masking out very high contrast image data